1. Oil supply route from pump to valve block
P1 straight oil supply passage: priority oil supply relationship: supply oil according to boom, bucket and travel order, and return oil is controlled by valve D.
Parallel oil supply channel: in parallel oil supply relationship, it gives priority to the boom, and then supplies oil to the bucket and traveling through the orifice u and check valve.
P2 direct oil supply channel: supply oil according to the priority of swing, backup, stick and travel, and the oil return is controlled by valve C.
Parallel oil supply channel: in parallel oil supply relationship, it gives priority to the boom, and then supplies oil to the bucket and traveling through the orifice u and check valve.
P2 direct oil supply channel: supply oil according to the priority of swing, backup, stick and travel, and the oil return is controlled by valve C.
Parallel oil supply channel: it gives priority to rotation, and then supplies oil to backup, stick and traveling through orifice V and check valve.
The function of the check valve of the parallel oil supply passage is to prevent the pressure oil introduced into the valve inlet from flowing out to other valve stems.
2. Boom confluence
Under the action of the pilot operated oil pressure PE controlling the boom valve lifting, the three two-position two-way valves a, B and C are in the closed position. Valve a cuts off the compression oil pressure of cartridge valve X so that valve x can be opened. The pressure oil of P2 pump is connected to the boom valve through cartridge valve x for confluence. The cartridge valve is adopted for confluence, with small impact during confluence. At the same time, valve C is closed so that P2 cannot return oil through the direct oil supply passage, and valve B is closed so that P: pump pressure oil cannot be supplied to the stick valve.
Stick confluence:
There is no pilot control oil pressure in the boom valve, and valve B is in the open position under the action of spring. P1 pump can supply oil to the stick valve through valve B and through the check valve (to prevent P2 pump oil from flowing to P1 pump oil circuit). At the same time, there is pilot control oil pressure PA in the stick valve (oil pressure can be led out in both stick control directions through the shuttle valve) Under the action, valve D is closed, so that the direct oil supply passage of P pump cannot return oil through valve D, but can enter the stick valve through the check valve. Therefore, P1 pump can supply oil to the stick valve in two ways: through the parallel oil supply passage and direct oil supply passage of P1, it can supply oil to the stick valve.
Bucket confluence:
As shown in the figure, P2 is directly connected to the end X of the oil supply circuit, and an oil circuit is led to the bucket valve through the check valve. As shown by the XY dotted line in the figure, the pilot control oil pressure PX controlling the excavation of the bucket valve is added to the two position two-way valve C, so that when the bucket is excavating, the C valve is closed, and the P2 pump pressure oil flows to the bucket valve for combined oil supply.
3. Walking straightness
In order to ensure the straight-line driving performance when the traveling and working devices act at the same time, Toshiba UX series adopts to connect the oil inlets of the two traveling valves through two position two-way valve e to form parallel oil supply. Valve e is usually in the disconnected position under the action of spring, and the oil inlets of the two traveling valves are not connected. Valve e is operated by pilot oil pressure pr. when PR establishes oil pressure, the oil inlets of the two traveling valves are connected For parallel oil supply, the establishment of PR oil pressure is linked with the valve stem operation. As long as the two travel valves are not in the middle position and one of the boom, stick, bucket and swing is not in the middle position, the return oil circuit of PR can be cut off and the oil pressure can be established (see the dotted line passing through each valve in Figure 1).
Here, we use a more concise way to express the composition of UX multi-channel valve hydraulic system, the design idea and oil circuit connection mode of the valve, so that we can clearly understand the multi-channel valve hydraulic system.
